Clock compensating pendulum.



G. LAZZARO.

CLOCK GOMPENSATING PENDULUM.

APPLICATION FILED NOV. 22, 1907.

Patented Feb. 20, 1912;

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CARMELO LAZZARO, OF MENDOZA, ARGENTINA.

CLOCK COMPENSATING PENDULUM.

Application filed November 22, 1907.

Specification of Letters Patent.

Patented Feb. 20, 1912.

Serial No. 403,422.

To all whom it may concern:

Be it known that I, OARMELO LAZZARO, citizen of Italy, and resident of Calle San Martin 74, Mendoza, Republic of Argentina, have invented a certain new and useful Clock Compensating Pendulum, of which the following is a specification.

This invention relates to compensating pendulums for clocks and the objects of the invention are to compensate for variations in the length of the pendulum due to changes in temperature.

To these ends the invention consists of the devices substantially as hereinafter fully described and claimed in this specification and shown in the accompanying drawings, in which Figure 1 is a front elevation of a pendulum embodying the invention, with the weight removed. Fig. 2 is a detail plan view of the connecting means between the pendulum rod and the spiral; Fig. 3 is a detail perspective view of one clamp, with the top plate removed; Fig. 4 is a detail perspective view of a top plate for a clamp; Fig. 5 is a detail front view of the pendulum with the weight attached to the spiral; Fig. 6 is a detail side view of the device with the clamps removed; and Fig. 7 is an enlarged detail transverse sectional view on line 7-7 of Fig. 1.

Referring to the drawings, the pendulum rod C is suspended in the usual manner, and the anchor rod B is connected as usual to the anchor A. In order to compensate for variations in the length of the pendulum rod, a spiral D is suspended from the lower end of the rod. This spiral is preferably cut in a lathe in any suitable manner from a cast tube of homogeneous metal, such as zinc, or preferably pure copper, avoiding amalgams, and the metal should not be laminated, or hammered after the metal is cast.

The spiral should be of substantially the following dimensions :-outside circumference, one-fourth of twice the length of the pendulum rod, less the width of the spiral, 1 cm. about; depth 1 mm. moreor less; width of the individual convolutions 1 mm. more or less. The convolutions should be separated as little as possible in cutting the spiral.

The lower end G of the pendulum rod C is screw threaded and provided with an adjusting nut H, and bet-ween said nut H and a lock nut J is held a piece F to which is connected an arm E extending outwardly and rearwardly at an angle. As shown in Fig. 6, the spiral D is passed over the arm E and one end a; of said spiral is connected at the rear to the outer end of arm E, while the front extremity of the spiral is provided with a short forwardly extending arm Z to which is suspended a weight Y preferably in the form of a disk.

In order that the spiral may expand and contract circumferentially, but be constrained laterally, I provide guide clamps K in the form of U-shaped pieces of metal, perferably iron, adapted to hold curved plates M and L upon the inner and outer peripheries of the spiral, as shown more fully in Fig. 7. The plates M and L are preferably cut from a sheet of cast metal, and each inner plate M has one clamp K soldered thereto, the other clamp K preferably being loose, for freedom of movement of the convolutions. The plates M and L may be provided with thin strips of lead a fastened thereto to prevent direct contact between the plates and the spiral, although springs could be substituted for the strips of lead. The plates M and L are also preferably provided with the points or projections Z) suitably spaced to enter between the convolutions and space them apart and also prevent lateral displacement of the clamps and plates." Talc dust is preferably placed between the plates M and L and the convolutions to facilitate the circumferential movement of the convolutions relatively to the plates and clamps. Adjusting screws 0 and d are provided on the clamps K, which screws should only be adjusted sufficiently tight to maintain the clamps in position without interfering with the free circumferential movement of the convolutions within the clamps and relatively to the plates.

In this instance the anchor rod B is preferably loosely connected to one of the clamps, as by means of the hook 0, Fig. 3, through which the anchor rod loosely slides. By this means variations in the spiral do not affect the movements of the anchor rod, the sole object of the anchor rod being to communicate oscillatory movement to the apparatus.

In the operation of the apparatus, the spiral D expands and contracts with expansion and contraction of the pendulum rod C. As the pendulum rod lengthens by expansion, the spiral eXpands longitudinally and the convolutions have movement relative to the clamps K, since said convolutions may slide through the clamps between the plates M and L, but may not separate laterally. The diameter of the spiral will therefore increase with expansion, but the length of the pendulum, that is the distance between the point of suspension and center oi mass of the pendulum bob, (comprising the spiral and the weight) will remain constant. Conversely, contraction of the pendulum rod is compensated for by contraction of the.

spiral, thus maintaining the length of the pendulum substantially constant.

I claim and desire to obtain by Letters Patent the following:

1. A compensating pendulum for clocks, comprising a pendulum rod, a compensating spiral suspended by said rod, and means for permitting longitudinal expansion and contraction of the spiral while restraining lateral movement of the convolutions relatively to each other.

2. A compensating pendulum for clocks,

comprising a pendulum rod, a compensating spiral suspended at one end from said rod, a weight attached to the other end of said spiral, and guide clamps engaging the convolutions for permitting longitudinal movement of the convolutions while restraining lateral movement.

8. A compensating pendulum for clocks, comprising the pendulum rod, a compensating spiral suspended from said rod, guides for said spiral, a weight connected to the spiral and an anchor rod engaging the spiral.

&. A compensating pendulum for clocks, comprising the pendulum rod, a compensating spiral, an arm for suspending said spiral from the pendulum rod, and guide clamps for guiding and spacing the convolutions oi the spiral.

Signed at Mendoza Republic of Argentina this 24 day of September A. D. 1907.

' CARMELO LAZZARO.

Witnesses ENRIQUE G. VARALLO, SALVADOR SEGURA B.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

